1. Field of the Invention
The present invention relates generally to a method for making a dental restoration or prosthesis, such as a crown or a bridge. In particular, the present invention relates to a method for making a dental restoration with a second material filling a pocket in the dental restoration.
2. Related Art
Minimal intervention is a key phrase in today's dental practice. Minimal intervention dentistry (MID) focuses on the least invasive treatment options possible in order to minimize tissue loss and patient discomfort. Concentrating mainly on prevention and early intervention of caries, MID's first basic principle is the remineralization of early carious lesions, advocating a biological or therapeutic approach rather than the traditional surgical approach for early surface lesions. One of the key elements of a biological approach is the usage and application of caries inhibiting (or remineralizing) agents to tooth structure (enamel and dentin lesions). These agents are part of a new era of dentistry aimed at controlling the demineralization/remineralization cycle, depending upon the microenvironment around the tooth.
Dental caries is a multifactorial disease caused by the interaction of dietary sugars, dental biofilm and the host's dental tissue within the oral environment (Buzalaf M A R, Fluoride and the Oral Environment, Monogr Oral Sci, Basel, Karger, 2011, vol 22, p 97-114). It is the cumulative result of consecutive cycles of demineralization and remineralization at the interface between the biofilm and the tooth surface. Oral bacteria excrete acid after consuming sugar, leading to demineralization (Fejerskow O, Kidd, E A, Nyvad B, Baclum V, Defining the disease: an introduction: in Fejerskov O, Kidd E (eds): Dental Caries—The Disease and its Clinical Magement, ed 2, Oxford, Blackwell Munksgaard, 2008, p 3-6). Upon this acid challenge, the hydroxyapatite crystals are dissolved from the subsurface. Remineralization is the natural repair process for non-cavitated lesions. It relies on calcium and phosphate ions, assisted by fluoride, to rebuild a new surface on the existing crystal remnants in the subsurface. The remineralized crystals are less acid soluble than the original ones (Featherstone J D, Dental Caries: a dynamic disease process, Aust Dent J, 2008; 53(3):286-91).
When the enamel and dentin no longer have adequate structure to maintain their mineral framework, cavitation takes place and remineralization is an insufficient treatment. Tooth preparation and restoration are now required. Although most restorative materials are inert with respect to the biological tissues of the tooth, some are bioactive. Bioactive restorative materials actually interact with or affect the biological tissues. They effectively work with the dental hard tissues to harden and “heal” them. The most widely used bioactive (caries inhibiting) restorative materials are calcium, phosphate, and fluoride. These agents release calcium ions, phosphate ions, and fluoride ions, respectively. Silver, copper, and zinc can also be used to inhibit the caries causing microbes.
It is well established that topically applied fluoride ions as a typical example of CIMs (caries inhibition materials), through integration into the mineral component of enamel and dentin, can function to reduce the incidence and progression of dental caries. (J. M. Ten Cate, “Current concepts on the theories of the mechanism of action of fluoride,” ActaOdontologicaScandinavica, vol. 57, no. 6, pp. 325-329, 1999.) (C. González-Cabezas, “The chemistry of caries: remineralization and demineralization events with direct clinical relevance,” Dental Clinics of North America, vol. 54, no. 3, pp. 469-478, 2010). Fluoride complexes have the ability to promote dental tissue remineralization in addition to increasing the resistance of tooth structure to demineralization. (W. Evans, “Conference report: a joint IADR/ORCA international symposium—fluorides: mechanisms of action and recommendations for use,” Journal of Dental Research, vol. 68, no. 7, pp. 1215-1216, 1989). Fluoride can be made available to tooth surfaces through several methods, including via dentifrices, mouth rinses, and fluoridated water intake. It can also be used as a FRRM (Fluoride releasing restorative material) generally in the form of glass ionomer restorative material/cements or RMGI (resin-modified glass ionomer) restorative material/cements.
Some fluoride releasing dental materials are known. Some are fluoride ion releasing materials, mostly in a resin matrix. Often, the material is applied on the natural tooth directly inside a patients mouth. Some of these materials are an adhesive cement to seat a crown. For example, see: U.S. Pat. No. 4,515,910 (Raws et al); U.S. Pat. No. 4,572,920 (Zimmerman et at); U.S. Pat. No. 4,732,617 (Causton et al), U.S. Pat. No. 4,775,646 (Hench et al); U.S. Pat. No. 4,871,786 (Aasen et al); EP application 0,380,796 (Danielson); U.S. Pat. No. 5,304,586 (Hammesfahr et al); EP Application 0,509,516; U.S. Pat. No. 5,306,338 (Tsunekawa); International publication number WO 94/23944 (Sladek); U.S. Pat. No. 5,824,720 (Nowak et al); EP application 0,772,709 (Braden); EP application 0,873,107 (Mitra et al); U.S. Pat. No. 5,718,924 (Braden et al); U.S. Pat. No. 5,883,153 (Roberts et al); U.S. Pat. No. 5,908,879 (Kawashima et al); U.S. Pat. No. 5,738,113 (Connelly); U.S. Pat. No. 6,334,775 (Xu et al); International publication number WO00/69393 (Brennan et al); U.S. Pat. No. 7,255,562 (Rusin et al); U.S. Pat. No. 7,491,694 (Reynolds et al); U.S. Pat. publication 2008/0305053 (Lee et al); U.S. Pat. No. 8,217,173 (Xu et al); and International publication number 2012/101432.
Also, some calcium and phosphate releasing dental material are known. Some are calcium ion and/or phosphate ion releasing materials, mostly in a resin matrix. Some of the materials are applied on the natural tooth directly inside a patient's mouth. Some of these materials can be used as an adhesive cement to seat a crown. For example, see: U.S. Pat. No. 7,491,694 (Reynolds et al); U.S. Pat. No. 5,782,971 (Constanz et al); U.S. Pat. No. 7,892,346 (Insley et al); U.S. Pat. No. 8,609,071 (Reynolds); U.S. Pat. No. 7,416,602 (Murphy et al); U.S. Pat. No. 8,512,741 (Tan et al); U.S. Pat. No. 7,709,029 (Chow et al); U.S. Pat. No. 7,018,460 (Xu et al); U.S. Pat. No. 6,949,251 (Dalai et al); 2005040286 (Rusin et al); 20050020720 (Dickens et al); U.S. Pat. No. 6,793,725 (Chow et al); 20030167093 (Xu et al); 20020137812 (Chow et al); U.S. Pat. No. 6,325,992 (Chow et al); U.S. Pat. No. 6,077,989 (Kandel et al); U.S. Pat. No. 5,782,971 (Constanz et al); U.S. Pat. No. 5,652,016 (Imura et al); U.S. Pat. No. 5,545,254 (Chow et al); U.S. Pat. No. 5,508,342 (Antonucci et al); U.S. Pat. No. 5,496,399 (Ison et al); U.S. Pat. No. 5,336,264 (Constanz et al); U.S. Pat. No. 4,612,053 (Brown et al).
Also, some bioactive dental materials are known. Some bioactive dental materials are applied on a natural tooth directly inside a patient's mouth. Some of these materials can be used as an adhesive cement to seat a crown. For example, see: U.S. Pat. No. 6,709,644 (Day et al); U.S. Pat. No. 7,090,720 (Kessler et al); WO/2007/144662 (Hill et al); U.S. Pat. No. 7,329,129 (Cook et al); US20040065228 (Kessler et al); US20070221093 (Erdrich et al); U.S. Pat. No. 6,086,374 (Litkowski et al); U.S. Pat. No. 5,891,233 (Salonen et al); U.S. Pat. No. 5,735,942 (Likowski et al); U.S. Pat. No. 5,527,836 (Yamamuro et al); U.S. Pat. No. 5,074,916 (Hench et al); U.S. Pat. No. 5,145,520 (Kokubo et al); U.S. Pat. No. 5,527,836 (Yamamuro et al); US 20130171220 (Hill et al); WO/1202/002996 (Bringley et al).
A bioactive delivery device for delivering a bioactive solution to the maxillary or mandibular, periodontal and/or mucosal tissues is known. For example, see WO/2008/086566 (Cochrane et al).
Methods of making dental crowns are known. Some include an artificial tooth which comprises an outer shell of esthetic porcelain and an inner core selected from reinforcing strong porcelain, synthetic resin, and a combination of synthetic resin and reinforcing strong porcelain. For example, see U.S. Pat. No. 3,423,829 (Halpern et al).
A dental prosthesis structure is known including a metal base contoured in a desired form and having a glass veneer of substantially the same coefficient of expansion as the metal base bonded to the metal base. For example, see U.S. Pat. No. 3,481,772 (MaoNairn et al).
A preformed artificial crown for restoring a damaged tooth is known. For example, see U.S. Pat. No. 3,468,028 (Sunter).
A composition and method of preparing a model base in the manufacture of dental prosthesis is known in which the model base is made of alkali phosphate and alkaline-earth fluoride. For example, see U.S. Pat. No. 3,647,488 (Kristin et al).
A porcelain superstructure surrounding a metal substructure composed of a framework of relatively thin metal members interconnected to form concavities within the porcelain superstructure is known. U.S. Pat. No. 4,231,740 (Shoher et al)
See also U.S. Pat. No. 4,299,574 (Neihart); U.S. Pat. No. 4,600,389 (Schwartz); U.S. Pat. No. 4,654,007 (Sigler et al); U.S. Pat. No. 4,722,689 (Corbetta); U.S. Pat. No. 4,877,402 (Hirabayashi et al); U.S. Pat. No. 5,695,339 (Abera); U.S. Pat. No. 6,386,865 (Suh et al).
There is no agreement in the literature in regards to the question of what quantity of fluoride has to be released from a filling material in order for it to provide a reliable caries-inhibiting action (R. W. Phillips, “Restorative Materials Containing fluoride, Journal of American Dental Association 116 (1988) 762-763). In view of clinical findings with various fluoride-releasing filling materials, it is, however, to be noted that the quantity of fluoride which is released by glass ionomer cements can reduce the formation of secondary caries to an extent that is clinically relevant (G. Wesenberg et al., J. Oral Rehabil. 7 (1980) 175-184). Also, it has been shown that in the case of so-called composite filling materials that display no or very little fluoride release, there is a particular susceptibility to attack from secondary caries (E. A. M. Kidd, Br. Dent. J. 144 (1978) 139-142).
Fluoride (F—) release is a desirable attribute for a material used in some dental applications. In general, materials that release greater amounts of fluoride have greater caries prevention potential and are desirable. For direct treatment methods to be directly used inside the patient's mouth, there are many dental materials being used that release fluoride including silicate cements, glass ionomer cements, glass ionomer hybrid (resin-modified) cements, and fluoride releasing composite resins. These materials are used either for filling materials after removal of caries or for adhesive material between the crown and prepared tooth. Also, it has been well known that fluoride releasing materials, as one example of a caries inhibiting material, release fluoride ions and recharges the ions when the fluoride ion level is high inside the mouth from the fluoridated dentifrices over long period of time.